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Find the standard deviation of the following data. Round your answer to one decimal place. x 0 1 2 3 4 5 P(X

Sagot :

Answer:

[tex]\sigma = 1.8[/tex]

Step-by-step explanation:

Given

[tex]\begin{array}{ccccccc}x & {0} & {1} & {2} & {3} & {4}& {5} \ \\ P(x) & {0.2} & {0.1} & {0.1} & {0.2} & {0.2}& {0.2} \ \end{array}[/tex]

Required

The standard deviation

First, calculate the expected value E(x)

[tex]E(x) = \sum x * P(x)[/tex]

So, we have:

[tex]E(x) = 0 * 0.2 + 1 * 0.1 + 2 * 0.1 + 3 * 0.2 + 4 * 0.2 + 5 * 0.2[/tex]

[tex]E(x) = 2.7[/tex]

Next, calculate E(x^2)

[tex]E(x^2) = \sum x^2 * P(x)[/tex]

So, we have:

[tex]E(x^2) = 0^2 * 0.2 + 1^2 * 0.1 + 2^2 * 0.1 + 3^2 * 0.2 + 4^2 * 0.2 + 5^2 * 0.2[/tex]

[tex]E(x^2) = 10.5[/tex]

The standard deviation is:

[tex]\sigma = \sqrt{E(x^2) - (E(x))^2}[/tex]

[tex]\sigma = \sqrt{10.5 - 2.7^2}[/tex]

[tex]\sigma = \sqrt{10.5 - 7.29}[/tex]

[tex]\sigma = \sqrt{3.21}[/tex]

[tex]\sigma = 1.8[/tex] --- approximated